1. Field of the Invention
The present invention generally relates to a grating structure for splitting light.
2. Description of Related Art
Various grating structures have been introduced in industry. Gratings typically have rows of grating lines that diffract light. The diffracted light is generally distributed into a diffraction pattern forming a number of modes. One type of diffraction grating is a transmission grating. Typically, transmission gratings comprise grooves etched into a transparent material. As the elements of light in the incident spectrum strike the grooves at a certain angle, they are diffracted and, therefore, separated to various degrees. In many optical applications, light sources generate diffuse light with randomized polarizations. In these applications, typical gratings waste much of the light and, therefore, are not efficient in many beam splitting applications.
In view of the above, it is apparent that there exists a need for an improved grating structure.